<template>
  <div class="box" style="height:500px">
    <div class="xtx-slider">
      <ul class="slider-body" @mouseenter="mouseEnter" @mouseleave="mouseLeave">
        <li
          class="slider-item"
          v-for="(item, i) in sliders"
          :key="i"
          :class="{ fade: index === i }"
        >
          <img :src="item.imgUrl" alt="" />
        </li>
      </ul>
      <div class="slider-indicator">
        <span
        v-for="(item,i) in sliders"
        :key="item.id"
        :class="{active:index === i}"
        @click="indicatorFn(i)"></span>
      </div>
    </div>
  </div>
</template>

<script>
export default {
  props: {
    sliders: {
      type: Array,
      default () {
        return []
      }
    },
    time: {
      type: Number,
      default: 1500
    },
    isLopp: {
      type: Boolean,
      default: true
    }
  },
  name: 'XtxSlider',
  data () {
    return {
      index: 0 // 记录当前显示图片的下标
    }
  },
  methods: {
    // 点击小按钮,根据点击按钮的index来显示对应的图片
    indicatorFn (index) {
      this.index = index
    },
    // 开启定时器
    initLoop () {
      this.timer = window.setInterval(() => {
        this.index++
        // 当下标的大小大于数组长度减1的时候,让下标归0
        if (this.index > this.sliders.length - 1) {
          this.index = 0
        }
      }, this.time)
    },
    // 鼠标移入的时候,关闭定时器
    mouseEnter () {
      window.clearInterval(this.timer)
    },
    // 鼠标离开的时候,开启定时器
    mouseLeave () {
      this.initLoop()
    }
  },
  mounted () {
    this.isLopp && this.initLoop()
  }
}
</script>

<style scoped lang='less'>
.xtx-slider {
  width: 100%;
  height: 100%;
  min-width: 300px;
  min-height: 150px;
  position: relative;
  .slider {
    &-body {
      width: 100%;
      height: 100%;
    }
    &-item {
      width: 100%;
      height: 100%;
      position: absolute;
      left: 0;
      top: 0;
      opacity: 0;
      transition: opacity 0.5s linear;
      &.fade {
        opacity: 1;
        z-index: 1;
      }
      img {
        width: 100%;
        height: 100%;
      }
    }
    &-indicator {
      position: absolute;
      left: 0;
      bottom: 20px;
      z-index: 2;
      width: 100%;
      text-align: center;
      span {
        display: inline-block;
        width: 12px;
        height: 12px;
        background: rgba(0, 0, 0, 0.2);
        border-radius: 50%;
        cursor: pointer;
        ~ span {
          margin-left: 12px;
        }
        &.active {
          background: #fff;
        }
      }
    }
    &-btn {
      width: 44px;
      height: 44px;
      background: rgba(0, 0, 0, 0.2);
      color: #fff;
      border-radius: 50%;
      position: absolute;
      top: 228px;
      z-index: 2;
      text-align: center;
      line-height: 44px;
      opacity: 0;
      transition: all 0.5s;
      &.prev {
        left: 20px;
      }
      &.next {
        right: 20px;
      }
    }
  }
  &:hover {
    .slider-btn {
      opacity: 1;
    }
  }
}
</style>
